An investigation will be made of the properties and regulation of glycogen synthase kinases and phosphatase from skeletal muscle and liver. The relationship between the covalent phosphorylation-dephosphorylation of glycogen synthase and its activity changes will be studied using purified enzymes from skeletal muscle and liver. The phosphorylation sites which are responsible for interconversion between the I and D forms will be determined. The site phosphorylated in skeletal muscle synthase by the cAMP-independent kinase will be sequenced. A study of the physical properties - molecular weight and subunit structure and possible regulation by Ca ions of the cAMP-independent synthase kinase from skeletal muscle will be made. Hormonal regulation by insulin of cAMP-independent synthase kinase will be studied in perfused rat hemicorpus. The catalytic subunit and inhibitory protein components of skeletal muscle phosphoprotein phosphatase will be purified. Effects of the inhibitory proteins on the substrate specificity of the phosphatase will be investigated. An attempt will be made to label glycogen synthase with 32P in the perfused rat hemicorpus and in isolated rat hepatocytes. The 32P content and phosphorylation sites will be studied under several physiological conditions.